Forensic Science International: Reports最新文献

One of the primary goals of forensic laboratories performing DNA recovery and profiling is obtaining a high-quality DNA extract from crime scene samples. This is largely dependent on the sensitivity and reliability of the DNA extraction chemistry utilised, as well as the liquid handling and contamination minimisation techniques employed. Automation of DNA extraction methods on large liquid handling platforms allows high-throughput laboratories to apply sensitive chemistries to reliably process a large number of samples, while minimising manual processes and cross-contamination.

This study describes the first known implementation of the PrepFiler™ Automated Forensic DNA Extraction Kit on a Tecan Fluent® Gx 1080 Automation Workstation. Two Workstations were customised with the addition of novel “Safe Pipetting Modules” to eliminate sample crossover between wells, which is important in a forensic biology setting to reduce inadvertent DNA transfer. A comparison of DNA extraction efficiency between an optimised PrepFiler™ method and the DNA IQ™ System performed on a Perkin Elmer Janus® Integrator platform showed the optimised PrepFiler™ method consistently extracted a higher yield of DNA from a range of blood inputs, as well as blood and buccal swabs. The PrepFiler™ chemistry also more efficiently removed humic acid and haematin, reducing subsequent PCR inhibition. The subsequent implementation of the optimised PrepFiler™ method onto the Tecan Fluent® Gx workstations showed a further increase in sensitivity, with no evidence of DNA cross-contamination observed. However, the optimised PrepFiler™ method encountered difficulties extracting DNA from fabric substrates, with the PrepFiler Express™ chemistry extracting higher yields on the cartridge-based AutoMate Express™ System.

Overall, this study demonstrated the Tecan Fluent® Gx 1080 Automation Workstation is a sensitive, reliable and robust method for DNA extraction using the PrepFiler™ Automated Forensic DNA Extraction Kit, and the addition of the novel Safe Pipetting Module makes this platform an attractive option for forensic biology laboratories where minimising inadvertent DNA transfer is of paramount importance.

Heroin use is responsible for many drug-related deaths, so the determination of its biomarkers, except for 6-acetylmorphine, in biological samples, is of particular concern in toxicological laboratories worldwide, for a better investigation of these cases. Th use of 6-acetylmorphine as a heroin biomarker has some limitations due to its rapid bioconversion to morphine within a few hours, especially in blood samples. The need for new indirect biomarkers, like the ones that come from the processing of opium during the clandestine production of heroin, becomes imperative. A GC/MS method was developed and validated for the determination of meconin, thebaine, papaverine, acetylcodeine and noscapine, along with morphine, codeine and 6-acetylmorphine, in different biological samples of heroin users. For all analytes and all individual biological samples, the LOD and LOQ were 2.00 and 5.00 ng/mL, respectively, the calibration curves were linear (R²≥0.991) from 5.00 to 500.0 ng/mL, and absolute recoveries were higher than 91.9 %. The method was applied during the toxicological investigation of 34 forensic cases after positive immunoassay screening for opiates. The results indicate that meconin is the most frequently detected indirect biomarker of heroin use, as it was found in 91.2 % of all cases, whilst in 23.5 % of them no 6-acetylmorphine was detected. Papaverine was found in 67.6 % of all cases and is considered to be the second most important indirect biomarker of heroin use. The establishment of detecting meconin and papaverine in biological materials in parallel with the detection of morphine, codeine and 6-acetylmorphine can contribute to more conclusive results concerning heroin use in forensic cases.

In forensic science, accurate age estimation becomes crucial, especially in cases where information about the deceased is unavailable. The legal categorization of children into age groups, notably at 12 and 14 years, holds significant importance in various legal and social contexts. Despite the importance of such categorizations, the existing literature lacks ample studies addressing the specific classification of children into these legal age groups. This study aims to identify the key variables that distinguish between the categories of 12 and 14 years of age. Additionally, it seeks to calculate and compare the sensitivity, specificity, and overall accuracy of the discriminant function in accurately determining the required age. The oral panoramic radiographs (OPGs) of 3058 children aged between 5 and 16 years from six South Indian states were evaluated. The dataset was divided into train and test data sets. Dental maturity for each individual was estimated by considering the number of fully developed permanent mandibular teeth on the left side and the normalized measurement of the open apices of all seven teeth. Linear discriminant functions for the age groups of 12 and 14 years were computed using the training data. The discriminant functions for the 12-year age group demonstrated an accuracy of, 78.0 %, while those for the 14-year age group achieved an accuracy of .71.2 %. The sensitivity and specificity of the discriminant functions for the 12-year age group were 74.5 % and, 84.6 %, respectively. In the case of the 14-year age group, the sensitivity and specificity were 72.5 % and 70.0 %, respectively. This study concludes that the discriminant functions utilized herein exhibited commendable performance in accurately classifying individuals within the specified age groups of 12 and 14 years.

Lip print identification is one of the forensic identification tools recognized a long time ago. Few studies investigated the stability of lip prints, particularly the changes attributed to time or aging. To our knowledge, no previous studies speculated the changes in lip print following lip augmentation therapy, which has increased over the last few years. Therefore, the current study aimed to investigate the effect of lip augmentation therapy on lip print stability. The current study was a prospective longitudinal study that enrolled female volunteers who underwent a filling procedure for labial augmentation. A total of 24 volunteers' prints were analyzed using Suzuki and Tsuchihashi classification. Participants showed a mean age of 27.5 ± 6.0 years. The current study showed that no two lips exhibited the same pattern. Moreover, although the filling procedure for labial augmentation (FPLA) therapy preserved the predominant groove pattern, it significantly influenced the frequency of lip patterns in all lip quadrants. A significant decline in the number of lip grooves, notably Types I and I' was noticed. However, the predominant groove pattern was preserved. Quadrants A and D were the least affected lip parts. Type I′ was the predominant lip pattern over the study population, representing 83.3 %, followed by Type I, representing 16.7 % before and 12.5 % after augmentation without a statistically significant difference (p = 0.317). On the other side, Type III was the least presented pattern. The upper lip score had decreased significantly after augmentation from 71.5 ± 10.8–65.8 ± 10.2, and the lower lip score had decreased significantly from 67.4 ± 13.7–64.9 ± 13.5. Consequently, the overall lips score had decreased significantly from 139.0 ± 22.9–130.7 ± 21.1 after augmentation (p < 0.001). So, we recommend adopting more than one criterion to report a reliable, repeatable lip print, including the frequency of lip lines besides the predominant pattern. However, we advise giving more attention to the distinguished lip patterns (Types II, III, IV, and V) and considering the FPLA as one of the lip print modifiers.

Burned human remains have been studied by both forensic anthropologists and bioarchaeologists to understand how fire impacts and alters bone in different scenarios. Heat-induced changes can occur including differences in colour and shrinkage, where the extent of the latter varies in different studies. The current study aimed to bring information regarding this topic and to observe how the individual’s biological sex and age at death impact shrinkage. The variability of shrinkage was analysed, relating to temperature and duration of burning. The sample comprised of the patellae of 32 individuals (18 [56.3 %] females and 14 [43.8 %] males) with age at death between 60 and 93 (age grouped in decades) from the sub-collection of experimentally burned skeletons, part of the 21st Century Identified Skeletal Collection (ISC/XXI). The right patellae were subjected to experimental burning at different temperatures and durations using an electric muffle furnace. Both the right and left patellae had three measurements taken, maximum height, maximum thickness and maximum width, with a digital calliper. The shrinkage percentage was higher in males and among the younger individuals (60–79 years old of both sexes). The values of standard deviation were high which indicates high variability. Shrinkage occurred at every temperature with bigger values observed in the patellae that had been subjected to temperatures over 800ºC. However, three patellae showed an increase in size at temperature under 800ºC. These findings align with previous studies where a non-linear correlation between shrinkage and exposure duration was found. It is essential to underscore that the percentage of shrinkage exhibits substantial variability even under identical temperature and duration conditions, highlighting the critical significance of meticulous experimental design and thorough analysis.

A man in his forties with two lacerations in the occiput was found in a river. A forensic autopsy revealed that the cause of death was drowning, and the blood ethanol concentration was 1.5 mg/mL. The whole brain was fixed with formalin for 15 days using the standard immersion method to evaluate this. The fixed brains showed large holes in the deep white matter as artifacts. Research suggests that formalin-fixed brains from drowning cases tend to have “Swiss cheese-like” holes in the deep white matter. However, this study is the first to report a case that focuses on large holes as artifacts. The holes in the fixed brain may have been caused by postmortem invasion of freshwater indigenous bacteria and gas formation.

Determining the sex from an unidentified fingerprint recovered from a crime scene can assist in narrowing down the pool of potential suspects. The present study was conducted with the aim of determining sex using fingerprint epidermal ridge sweat pore density among the Indian population. For this purpose, plain prints from both the left and right thumbs were obtained from a total of 396 participants (191 males and 205 females), aged between 18 and 35 years, who were randomly selected for the study. Sweat pores were counted in a region of 3 × 3 mm². Data were analyzed using SPSS (Statistical Product and Service Solutions) version 26 for Windows and Microsoft Office Excel 365. The likelihood ratio (LR) was calculated to obtain the probability inferences of sex based on the number of sweat pores. Analysis revealed that a fingerprint containing ≤ 45 pores/9 mm² is more likely to be of male origin while one containing ≥ 49 pores/9 mm² is more likely to be of female origin. Moreover, the difference in the number of pores was found to be statistically significant between the two biological sexes. The methodology employed in this study helps demarcate a uniform region in all the samples thereby eliminating variability due to pattern type and recurving ridges.

Illegal activities associated with deforestation for the lumber and furniture industries pose significant threats to plant and animal biodiversity, as well as natural resources. Accurate identification of wood sources is vital, yet traditional laboratory techniques often fall short in precisely determining the chemical composition of samples for classification. This study aims to leverage ATR-FTIR spectroscopy alongside machine learning algorithms to construct a robust model for discerning the geographical origins of wood samples from India. By systematically comparing various machine learning classifiers, we address the limitations of subjective visual interpretation and evaluate their accuracy using wood spectral data. Logistic regression emerges as the most effective classifier for distinguishing Eucalyptus (75 % accuracy), Dalbergia (68 % accuracy), and Populus (81.5 % accuracy) species. Through a methodology encompassing data pre-processing, classifier selection, and performance evaluation, this research offers promising tools for combating challenges posed by illegal wood trafficking and transportation. The outcomes hold significant potential for enhancing wildlife crime prevention efforts by facilitating the tracing illicit timber sources, apprehension of perpetrators, and implementation of preventive measures.

Purpose

While illicit opioids have not been historically significant in Brazil, these numbers have increased in the last few years. This change in the drug scenario is mainly associated with synthetic opioids, a class of new psychoactive substances (NPS). In this context, the present article describes detailed information about the recent cases of synthetic opioids seized in Brazil, especially the nitazenes group.

Methods

All the analyses were carried out by the Superintendence of the Technical-Scientific Police - Narcotics Control Center (STSP-NCC) in São Paulo, between July 2022 and April 2023. The synthetic opioids were mainly found in herbal fragments.

Results

Nitazenes, were the most frequent drugs detected in the seizures that took place in the State of São Paulo. There was a total of 140 cases of opioids seizures and 95 % out of those belonging to the nitazene group, while only 5 % consisted of other opioids (morphine and fentanyl). Nitazenes were found 28.6 % isolated and 71.4 % mixed with other active compounds, being MDMB-4en-PINACA the most prevalent (30 % of the samples). Non-nitazenes were found 27.1 % mixed and 72.9 % isolated. Nitazenes and non-nitazene opioids were not found in association in any sample.

Conclusion

This is the first consistent report of nitazene opioids apprehensions in Brazil. Also, as far as we know, it is the first report in which nitazenes were detected in the form of herbal fragments. The effect of smoking a potent opioid together with synthetic cannabinoids is unpredictable and most users cannot be aware of what they are using.